1. Field of the Invention
The present invention relates to an apparatus and a method for testing a semiconductor device using a probe card, and particularly to positioning of the probe card.
2. Description of Related Art
The probe card has been used for the performance test of various semiconductor devices, such as a central processing unit and a memory. The probe card is provided with multiple probes, which are needle-like conductors. In the case of a test, the probe card must be accurately positioned so that these probes are connected to a semiconductor chip to be tested and predetermined input and output terminals of a package provided with the semiconductor chip. However, such positioning operation is becoming difficult along with the reduction of chip size, the increase in the number of terminals, and the spread of TAB (Tape Automated Bonding) technology, for example.
FIG. 10 illustrates the configuration of a test apparatus 101 according to a related art. A TAB tape 110 winds around a supply reel 111. A semiconductor chip to be tested is fixed (connected) to the TAB tape 110. The TAB tape 110 is fed out from the supply reel 111 in the direction indicated by the arrow so that the conductor pattern (electrode pad) is located at the bottom of the drawing, and supplied to a measurement point 113. An imaging apparatus 112 is placed at the measurement point 113. At the measurement point 113, the TAB tape 110 is absorbed and retained from above by a pressure plate 115. Then as illustrated in FIG. 11, the probes 121 of the probe card extending from bottom contact electrode pads 126 which are connected to input and output terminals of the semiconductor chip 125. At this time, the probes 121 and the electrode pads 126 are positioned by the method performed by a test worker to manipulate a suitable operation unit and displace the probe card while checking the video of the measurement point 113 displayed on a display.
FIG. 12 illustrates the shape of a tip of a common probe 121. As illustrated in FIG. 12, the tip of the probe 121 bends toward the electrode pad 126 in order to form a favorable contact with the electrode pad 126. Therefore, a slight up and down of the probe 121, and shallow depth of field of the imaging apparatus 112 can easily create variation in the position recognition of the tip of the probe 121. FIG. 13 illustrates a successful and an unsuccessful examples of the position recognition of the tips of the probes 121. If the positions of the tips of the probes 121 can be correctly recognized, each of the tip positions can be on one straight line 130. On the other hand, if the tip positions of the probes 121 cannot be correctly recognized, each of the tip positions cannot be on the straight line, as illustrated in the unsuccessful example of FIG. 13.
Japanese Unexamined Patent Application Publication No. 2002-181889 discloses a technique relating to the positioning of the probe card and the TAB tape in a test apparatus as the one explained above. FIG. 14 is cited from Japanese Unexamined Patent Application Publication No. 2002-181889 and illustrates the method to recognize the positional relationship between the probe card and the TAB tape. This technique adjusts an angle θ to be 0. The angle θ is determined by a straight line X connecting a certain probe 2A1 and a probe 2A2, which is the farthest probe from the probe 2A1, and a straight line Y connecting the electrode pads 1C1 and 1C2. Note that the probes 2A1 and 2A2 are to have contact with the electrode pads 1C1 and 1C2.
Further, Japanese Unexamined Patent Application Publication No. 2-65150 discloses the technique relating to the positioning of a chip in a wafer and a probe card. The technique disclosed in Japanese Unexamined Patent Application Publication No. 2-65150 forms multiple marks on the straight line passing through the center of a circular probe card, recognizes the positions of the marks by an imaging apparatus placed on a stage where the chip to be tested is mounted thereto, and displaces the chip on the stage according to the result of the recognition.